Spot-type disk brake

ABSTRACT

On a brake support (12) engaging over a brake disk (10) a piston (34) is supported and on the other side a floating caliper (14) is supported for axial displacement. In both cases slide guides (40) are provided for the supporting and each have a guide body (42) having a groove (46) parallel to the axis (A) of the brake disk (10) and a threaded pin (48) which extends transversely of the axial center plane (B) of the brake and engages into the associated groove (46). The slide guides (40) are surrounded in each case by a resilient sealing sleeve (54) which is protected by a heat shield (66) arranged between it and the brake disk (10). Associated with the threaded pins (48) are anti-rotation locks for securing the pins against turning and which comprise mounting members (56) secured to the brake support (12). The mounting members (56) carry at the same time the heat shields (66).

The invention relates to a spot-type disk brake comprising

a brake support which engages over a brake disk,

a floating caliper which on a first side of the brake disk comprises anactuator with a piston,

a first brake pad which is arranged on the first side of the brake diskand actuable by the piston,

a second brake pad which is arranged on the second side of the brakedisk and is actuable by displacement of the floating caliper, and

slide guides for supporting the piston on the brake support on the firstside of the brake disk and for supporting the floating caliper on thebrake support on the second side of the brake disk, the slide guidesbeing formed in each case by

a guide body comprising a groove at least approximately parallel to theaxis of the brake disk,

a threaded pin which extends transversely of the axial centre plane ofthe brake and engages into the groove and

a sealing sleeve which protects the parts of the guide body and threadedpin co-operating with each other from soiling and is protected by a heatshield arranged between it and the brake disk.

In disk brakes of this type the guide bodies may be arranged either onthe floating caliper or on the brake support. Accordingly the threadedpins are screwed into the brake support or the caliper In both cases thethreaded pins are screwed in to such an extent that together with theassociated guide body they provide an almost play-free slide guide. Inthis screwed-in position the threaded pins must be secured so that theydo not unintentionally become loose due to vibrations.

To set the necessary guide play and the exact movement direction of thefloating caliper with respect to the brake support both these componentsare held in a desired position by clamping means. The threaded pins arethen mechanically screwed in until the screw-in torque required for thispurpose exceeds a predeterm-ined value which shows that the guide isfree of play. Finally, the threaded pins are turned back a predeterminedangular amount to give the desired small guide play.

In a known disk brake of the aforementioned type (DE-GM No. 8,601,094)the threaded pins are secured directly at their threads. For thispurpose generally chemical substances are used which are applied inmicrocapsules to the threads. On assembly the microcapsules are squashedso that the chemical substances can react, the inner and outer threadsthereby being stuck to each other.

It has been found that in the known disk brake according to the preamblethe friction between the threaded pins and the threaded bores receivingthem fluctuates during the squashing of the microcapsules to such anextent that it is not possible to adjust the guide play with the desiredaccuracy with the aid of the screw-in torque.

In the known brake according to the preamble the heat shields are eachsecured to a collar which is secured around the associated guide body onthe floating caliper. This type of mounting requires an additionalassembly expenditure for each of the heating shields.

The invention is therefore based on the problem of reducing the assemblyexpenditure involved with the securing of the threaded pins andattachment of the heat shields.

The problem is solved according to the invention in a spot-type diskbrake of the type described at the beginning in that

there is associated with at least one of the threaded, pins a ananti-rotation lock which comprises a mounting member secured to thebrake support and cooperating with the pin to prevent accidentalrotation thereof, and

that the heat shield provided for protecting the sealing sleeve of saidthreaded pin is carried by the mounting member.

The use of anti-rotation locks reliably secures the threaded pinsagainst rotation. Each mounting member is at the same time a supportingcomponent for the associated heat shield which is either secured asseparate component to the mounting member, for example fixedly welded,or is made in one piece with the mounting member, for example by deepdrawing. In both cases by securing a mounting member on the associatedthreaded pin and on the brake support the associated heat shield can bebrought into position without any further assembly work.

In a preferred embodiment of the invention the mounting member comprisesa recess which is fitted onto a polygonal head of the associatedthreaded pin and is thereby deformed complementarily to the polygonalhead. The recess may be formed in a pot-shaped depression of themounting member which is pressed into a widening of a threaded borereceiving the associated threaded pin.

Preferably the or each mounting member is angled and bears on an endface and a side face of the brake support facing the brake disk.

The spot-type disk brake according to the invention can also be furtherdeveloped in that a common anti-rotation lock is associated with twothreaded pins on either side of the brake disk and comprises a pair ofmounting members engaging over the brake disk in bridge manner. The useof a common anti-rotation lock for two threaded pins arranged on eitherside of the brake disk secures said pins particularly reliably againstturning because they have axes which do not coincide and are thus notjointly rotatable with the bridge-like pair of mounting members. Bysecuring a common pair of mounting members to two threaded pins arrangedon either side of the brake disk the two associated heat shields arealso brought into position easily without further assembly work.

As in the disk brake known from DE-GM No. 8,601,094 on each side of thebrake disk two slide guides for the piston and for the floating caliperrespectively are provided. In this case the invention can be furtherdeveloped in that all the slide guides each have a threaded pin and thattwo pairs of mounting members are provided, each pair connectingtogether a pair of threaded pins and carrying a pair of heat shields.

Examples of embodiment of the invention will be explained hereinafterwith the aid of the schematic drawings, wherein:

FIG. 1 is a plan view of a spot-type disk brake shown partially assection in the plane I--I of FIG. 2,

FIG. 2 is an end view of the disk brake shown partially in section inthe plane II--II in FIG. 1,

FIG. 3 is the section III--III of FIG. 1,

FIG. 4 is a detail in side view according to the arrow IV of FIG. 1 and

FIG. 5 is a variant of FIG. 4.

A brake support 12 mounted on a vehicle and a floating caliper 14displaceable parallel to the axis A of the brake disk 10 engage over theouter edge of said brake disk 10, only indicated in the drawing. Twobrake pads 16 and 18 arranged on either side of the brake disk 10 eachhave a brake lining 20 and 22 respectively and a support plate 24 and 26respectively. Extending through the support plates 24 and 26 is aU-shaped retaining stirrup member 28 which is secured to the floatingcaliper 14.

The brake pad 16 is supported with its support plate 24 on a pistoncarriage 30 which by means of a screw 32 is secured to a piston 34 of ahydraulic actuator 36. The actuator 36 comprises a cylinder 38 which isformed integrally with the floating caliper 14 and extends parallel tothe axis A of the brake disk 10. The second brake pad 18 is supportedwith its support plate 26 on the other side of the brake disk 10directly on the floating caliper 14.

The piston carriage 30 is guided by means of two slide guides 40 on thebrake support 12. The two slide guides 40, as apparent in particularfrom FIG. 2, are arranged symmetrically with respect to a centre plane Bof the disk brake which contains the axis A of rotation of the brakedisk 10; the axis C of the actuator 36 is slightly forwardly offset withrespect to the centre plane B in the main direction of rotation D of thebrake disk 10. The main direction of rotation D is the direction inwhich the brake disk 10 rotates when the vehicle to be retarded istravelling forwards.

Each of the slide guides 40 has a guide body 42 which is secured on thepiston carriage 30 by means of a stud 44 disposed at right-angles to thecentre plane B and comprises a groove 46 parallel to the axis A. Athreaded pin 48 with a conical end formed thereon engages into thegroove 46. The threaded pin 48 is screwed into the brake support 12 atright-angles to the centre plane and has a hexagonal head 50 having aconical centering shoulder 52. The guide body 42 and the end of thethreaded pin 48 co-operating therewith are sealingly enclosed by asleeve 54 of rubber or similar resilient material and thereby protectedfrom soiling and dirt.

Two further slide guides 40 which correspond to those described and aretherefore provided with the same reference numerals guide the floatingcaliper 14 on the brake support 12 on the side of the brake disk 10remote from the actuator 36 in the same manner as the piston carriage 30is guided on the brake support 12 on the first side of the brake disk10. Thus, a pair of slide guides 40 is arranged on either side of thecentre plane B of the disk brake.

In accordance with FIGS. 1 to 4 a common anti-rotation lock isassociated with each pair of slide guides 40 and comprises a bridge-likepair of mounting members 56 pressed from sheet metal. Each pair ofmounting members 56 comprises a centrepiece 56' which bridges the brakedisk 10, bears on either side thereof on an end face 57 of the brakesupport 12 and comprises there in each case a pot-shaped depression 58.The two pot-shaped depressions 58 of each pair of mounting members 56are pressed onto the hexagonal head 50 of one of the threaded pins 48and for this purpose comprise a recess 60 which is circular in theunused state and the diameter of which corresponds to the key width ofthe hexagonal head. When pressed on to the hexagonal head 50 the edgesof the latter penetrate the edge of the recess 60, the respectivethreaded pin 48 thereby being locked against rotation. The pressing onof the depression 58 onto the associated hexagonal head 50 isfacilitated by the conical centering shoulder 52 of the latter.

Each of the securing members 56 is secured against unintentionalwithdrawal in the direction away from the centre plane B in that each ofthe pot-shaped depressions 58 is received with interference fit in awidening 62 of the threaded bore into which the associated threaded pin48 is screwed.

Each mounting member 56 bears additionally on a side face 63 of thebrake support 12 parallel to the brake disk 10 and for this purposecomprises a tab 64 which extends parallel to the brake disk 10 and onwhich are embossed warts 65 directed away from the brake disk 10Integrally formed with the tab 64 and thus with the mounting member 56as a whole is a heat shield 66. The heat shield 66 is stiffened bybeading or edging and extends in the direction towards the centre planeof the disk brake 10 to such an extent that it shields one of thesleeves 54 from the radiant heat emanating from the brake disk 10.

The variant according to FIG. 5 differs from the embodiment illustratedin FIGS. 1 to 4 in that each mounting member 56 is an independentcomponent, i.e. is not connected to the mounting member opposite it by abridge 56'.

I claim:
 1. Spot-type disk brake comprisinga brake support (12) whichengages over a brake disk (10), a floating caliper (14) which on a firstside of the brake disk (10) comprises an actuator (36) with a piston(34), a first brake pad (16) which is arranged on the first side of thebrake disk (10) and actuable by the piston (34), a second brake pad (18)which is arranged on the second side of the brake disk (10) and isactuable by displacement of the floating caliper (14), and slide guides(40) for supporting the piston (34) on the brake support (12) on thefirst side of the brake disk (10) and for supporting the floatingcaliper (14) on the brake support (12) on the second side of the brakedisk (10), the slide guides (40) being formed in each case by a guidebody (42) comprising a groove (46) at least approximately parallel tothe axis (A) of the brake disk (10), a threaded pin (48) which extendstransversely of the axial centre plane (B) of the brake and engages intothe groove (46) and a sealing sleeve (54) which protects the parts ofthe guide body (42) and threaded pin (48) co-operating with each otherfrom soiling and is protected by a heat shield (66) arranged between itand the brake disk (10), characterized in that there is associated withat least one of the threaded pins (48) an anti-rotation lock securingthe pin against turning and which comprises a mounting member (56)secured to the brake support (12), and the heat shield (66) provided forprotecting the sealing sleeve (54) of said threaded pin (48) is carriedby the mounting member (56).
 2. Spot-type disk brake according to claim1, characterized in that the mounting member (56) comprises a recess(60) which is fitted onto a polygonal head (50) of the associatedthreaded pin (48) and is thereby deformed complementarily to thepolygonal head (50).
 3. Spot-type disk brake according to claim 2,characterized in that the recess (60) is formed in a pot-shapeddepression (58) of the mounting member (56) which is pressed into awidening (62) of a threaded bore receiving the associated threaded pin(48).
 4. Spot-type disk brake according to claim 1, characterized inthat the mounting member (56) is angled and bears on an end face (57)and on a side face (63) of the brake support (12) facing the brake disk(10).
 5. Spot-type disk brake according to any one of claims 1 to 4,characterized in that a common anti-rotation lock is associated with twothreaded pins (48) on either side of the brake disk (10) and comprises apair of mounting members (56) engaging over the brake disk (10) inbridge-like manner.
 6. Spot-type disk brake according to claim 5 inwhich on each side of the brake disk (10) two slide guides (40) arearranged for the piston (34) and the floating caliper (14) respectively,characterized in that all the slide guides (40) each have a threaded pin(48) and that two pairs of mounting members (56) are provided, of whicheach pair connects a pair of threaded pins (48) together and carries apair of heat shields (66).